The present invention relates to a novel system of true percutaneous spinous stabilization that allows for both spinous process immobilization as well as interspinous process distraction. In one embodiment the system comprises two or more staples or staple-like devices, each with a hole at their head ends and allowing for passage of a connecting rod therethrough. The connecting rod will serve to couple the two aligned yet spaced staples so that they act as a unit. A small locking screw is provided to lock the heads of the staples to the rod. A locking wedge can also be utilized for tightly securing the staples to the rod. In this embodiment, the small locking screws, when tightened into their respective holes in the heads of the staples, cam against the surface of the locking wedge and thereby lock the locking wedge (inside the head of the staples) securely against the common connecting rod. A cap (for accepting and securing the pointed ends of the staples, after they pass through the processes of the patient) and an end or stabilizing plate (to more uniformly distribute the forces of compression/contraction resulting from the staples acting on the end plate) serve to secure the staples at the desired locations.
The device can be percutaneously delivered and/or installed into the patient by use of a set of tools, i.e., a delivery system which allows for the delivery of the components in a relatively minimally invasive manner. As mentioned, the stabilizing plate rests against the spinous processes, on the opposite side from the staples' entry, and the plate via the locking caps secure the free ends of the staples to compress the spinal processes. The locking nuts are placed over the ends of the staples, on one side of the stabilizing plate to secure the entire construct in place and to keep the staples from backing out and/or becoming loose.
In one embodiment, a carrier and manually operable surgical like clamp, in the preferred form resembling a centrally linked or hinged pair of pliers, is provided to introduce the staples, connecting rod, stabilizing plate and locking caps or nuts into position about the spinal processes and to then allow the physician to manually compress the finger grips of the clamp to draw the staples (held together as a unit by the connecting rod) through the processes, and to clamp them through the stabilizing plate and into the locking caps or nuts. This then holds the unit together. One side of the clamp holds the staples, secured on the connecting rod by the small locking screws and/or the locking screws cooperating with the locking wedge to the connecting rod, and the other side or the opposing side of the clamp, the stabilizing plate and spaced locking nuts are held (spaced apart by the distance of the points of the staples held on the rod). As mentioned, a percutaneous delivery system (shown and described in non-provisional U.S. patent application Ser. No. 11/650,096 filed Jan. 5, 2007, claiming priority on U.S. Provisional Patent Application Ser. No. 60/756,711 filed Jan. 5, 2006, whose teachings, drawings and specification are incorporated by reference herein) can be employed with the stabilizing system described herein. That delivery system basically includes a delivery tube having a central working channel which ultimately (i.e., by sequentially using the other elements of that system) allows for the introduction of the carrier clamp, along with the associated hardware i.e., the staples, the connecting rod, the stabilizing plate and the locking caps, in a percutaneous manner. The present system also may include a screwdriver like device which is adapted to travel along the delivery tube and tighten and lock the locking screws of the staples to the rod and or the locking caps/nuts to the tips or ends of the staples. Distraction implements may also be employed and provided which are adapted to travel along the carrier tube of the percutaneous delivery system and grab a staple, allowing for one stable to be selectively and carefully pulled to allow for distraction between adjacent and otherwise aligned yet spaced staples.
The provided staples for the stabilization described herein further include a staple pre-fixed at a spaced interval to a common connecting rod before insertion of those components into the working channel of the delivery tube. In one embodiment, the locking screw component serves to secure the staple(s) to the connecting rod, acting through a camming mechanism which directs a locking wedge in the head of the staple to press against and hold the staple in place on the connecting rod. Also, the staple(s) can be fixed to the rod after insertion into the working channel, the latter being accomplished by the locking wedge and laterally directed small locking screw facing the working end of the working channel of the carrier tube so that the physician can lock the staples to the rod, by turning the locking screws, thereby camming the locking wedge to the rod, after the components are in place about the patient's processes.